Buffers Flashcards
What happens when strong acids are placed in water?
Strong acids give a large number of H3O+ ions when placed in water
What happens when weak acids are placed in water?
They only partially dissociate when placed in water
What happens to H+ in water?
H+ always combines with an H2O molecule to form H3O+
What does the ionisation constant show?
It shows the direction of the reaction
What is Ka?
The acid ionisation constant
What is Kb?
The base ionisation constant
What does a large value of Ka mean?
It means there are many H+ ions in solution -> a strong acid
What does a large Kb value indicate?
It indicates many OH_ ions -> a strong base
What is a weak acid?
One that only partially dissociates in water
Give an example of a weak acid.
Ethanoic acid
What is the conjugate base of a weak acid?
A strong base
What is the conjugate acid of a weak base?
A strong acid
What is a buffered solution?
A buffered solution resists change in pH when small amount of acids or bases are added or when dilution occurs
What are buffered solutions made of?
3
A mixture of weak acid and its salt or a weak base and its salt
An acid and its conjugate base
A base and its conjugate acid
How do buffers work?
They work by removing small quantities of H+ and OH- ions that are added to it
Give an example of an acid buffer.
Ethanoic acid and NA ethanoate
Give an example of an alkaline buffer.
Ammonium and ammonium chloride mixture
What is the main buffer in blood?
Carbonic acid/hydrogen carbonate system
What is the pH of blood?
7.4
What pH is considered alkalosis?
7.45
What pH is considered acidosis of blood?
7.35
Why is maintenance of correct pH important?
3
Enzyme reactions
Growth of bacteria in culture media
Survival of various organism in the body
What is pH?
The power of hydrogen
